X - ring Motohooligan airbox

The x - ring ( O - ring ) between throttle bodies and airbox, could anyone tell me the dimensions on it. I ordered a pair but will have to wait 2-4 weeks and maybe longer. I will get me another pair back here in Sweden but would be nice to get the "right" dimensions.

Thanks

These ones http://www.motohooliganperformance.com/ ... duct_id=78